A246897 Number of length 5+4 0..n arrays with some pair in every consecutive five terms totalling exactly n.
416, 16621, 173056, 1216081, 4971120, 17677453, 47799488, 120392449, 259777600, 536775181, 1005318336, 1828277521, 3107102096, 5168689261, 8183025280, 12745702273, 19117702368, 28308317869, 40691100800, 57882676561, 80386887856
Offset: 1
Keywords
Examples
Some solutions for n=3 ..3....2....0....3....2....0....0....1....2....0....0....0....0....0....2....0 ..2....2....0....2....1....3....3....0....0....3....0....0....2....1....3....3 ..2....2....1....0....2....2....1....2....0....2....0....3....1....2....0....0 ..2....1....2....0....1....1....0....0....1....2....2....0....2....2....1....1 ..1....0....3....3....0....0....1....1....1....0....3....3....0....2....1....2 ..0....1....2....2....1....0....2....2....3....1....3....3....0....3....3....1 ..2....3....3....3....3....3....1....2....2....1....0....1....0....1....0....2 ..2....0....0....1....1....1....1....1....0....3....3....0....3....3....0....0 ..1....0....1....1....0....0....0....3....3....1....1....0....3....0....2....2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..65
Formula
Empirical: a(n) = 2*a(n-1) +5*a(n-2) -12*a(n-3) -9*a(n-4) +30*a(n-5) +5*a(n-6) -40*a(n-7) +5*a(n-8) +30*a(n-9) -9*a(n-10) -12*a(n-11) +5*a(n-12) +2*a(n-13) -a(n-14)
Comments